SIP + Lumpsum Calculator

A real investment plan often starts with money already available and continues with future contributions. You may receive a bonus, sell an asset, or move idle cash into a fund, then continue a monthly SIP from salary. The SIP + Lumpsum Calculator combines those two streams: one initial investment and a recurring contribution schedule. It then projects the future balance using the annual return, term, SIP frequency, deposit timing, and compounding frequency entered in the form.

Enter both contributions in dollars because the displayed results use dollars. The growth mathematics is currency-neutral, but mixing currencies would make the projected balance misleading.

How to use this calculator

Enter the initial lumpsum first. This amount is assumed to be invested for the full term. Enter the SIP amount next. Choose the expected annual return, then enter the term in years. Choose how often SIP deposits happen: yearly, quarterly, monthly, biweekly, or weekly. Select whether deposits occur at the end of each period or at the beginning. Finally, choose the compounding frequency for the annual return.

The result shows the projected future balance, future value of the initial lumpsum, future value of SIP deposits, total invested, total return, and number of SIP deposits. Because the calculator rounds the number of deposits to a whole number, unusual terms can create a rounded deposit count. For example, 10.1 years of monthly deposits becomes 121 deposits, not a fractional deposit.

Use the lumpsum investment calculator when there are no recurring deposits. Use the mutual fund calculator when you want a simpler monthly contribution model with an expense ratio. For a goal-first view, use the savings goal calculator.

Formula used by this page

The compounding growth factor for the lumpsum is:

$\text{growth factor} = \left(1 + \frac{\text{annual return}}{100 \times \text{compounds per year}}\right)^{\text{compounds per year} \times \text{years}}$

For continuous compounding, the factor is:

$\text{growth factor} = e^{\left(\frac{\text{annual return}}{100} \times \text{years}\right)}$

The future value of the initial investment is:

$\text{future value of lumpsum} = \text{initial lumpsum} \times \text{growth factor}$

The calculator derives an equivalent periodic rate for the SIP schedule:

$\text{SIP periodic rate} = \text{growth factor}^{\frac{1}{\text{transactions}}} - 1$

For end-of-period deposits, SIP future value is:

$\text{future value of SIP} = \text{SIP amount} \times \frac{(1 + \text{SIP periodic rate})^{\text{transactions}} - 1}{\text{SIP periodic rate}}$

For beginning deposits, the code multiplies that SIP value by one more period of growth:

$\text{beginning SIP value} = \text{future value of SIP} \times (1 + \text{SIP periodic rate})$

The final balance is:

$\text{future balance} = \text{future value of lumpsum} + \text{timing-adjusted SIP value}$

Worked example

The default values are a $1,000 initial lumpsum, $100 SIP amount, 10 percent expected annual return, 10 years, monthly SIP frequency, end-of-period deposits, and monthly compounding. Monthly compounding creates a growth factor of about 2.7070414908622435. The lumpsum future value is therefore about $2,707.04.

Monthly SIP frequency over 10 years creates 120 transactions. The SIP periodic rate derived from the growth factor is about 0.0083333333, matching a 10 percent annual rate compounded monthly. The end-of-period SIP future value is about $20,484.50. The total future balance is $2,707.04 plus $20,484.50, or about $23,191.54. Total invested is $1,000 plus $100 × 120, or $13,000. Total return is about $10,191.54.

If you keep every input the same but switch deposit timing to beginning, the SIP portion is multiplied by one additional monthly growth factor. The SIP future value rises to about $20,655.20 and the total future balance becomes about $23,362.24. That difference exists because every SIP deposit receives one extra period of compounding.

Tax, lock-in, and market context

The projection is not a guarantee. Indian mutual fund SIP and lumpsum investments are market-linked. NAV can fall after a lumpsum purchase, and SIP instalments can buy at different NAVs over time. The calculator assumes a smooth return, while real portfolios move unevenly. It also ignores expense ratios unless you lower the return assumption yourself.

Tax treatment depends on the scheme category, holding period, capital gains rules, and current law. Some products have lock-ins; some schemes have exit loads for early redemption. Rates, tax rules, fund expenses, and market assumptions change. For a near-term goal, use a lower return assumption and consider whether market risk is appropriate.

Practical tips

• Use conservative return assumptions for goals with fixed dates.
• Test both beginning and end timing so you understand the contribution-date effect.
• Do not compare only final balances; compare risk, liquidity, tax, and costs too.
• Rebalance if a large lumpsum changes your asset allocation.
• Keep documentation of SIP dates, amounts, and scheme details for tax records.

This calculator is informational, not financial advice.

Sources

• SEBI, Mutual Fund Regulations, 1996 — regulatory framework for mutual funds in India.
• AMFI, NAV history — official industry access point for fund NAV data.
• SEBI Investor Website, Investor education portal — investor-awareness context for market-linked investing.